Breakfast Lecture

Mark Schure has worked in separation science for over 35 years in industry and academics. Over a 28 year period he has worked for Digital Equipment Corporation, the Rohm and Haas Company and The Dow Chemical Company. Dr. Schure has been an Adjunct Professor in the Department of Chemical and Biomolecular Engineering at the University of Delaware for over 20 years. He has published over 110 papers, has 4 patents and recently edited the book “Multidimensional Liquid Chromatography.”

His scientific interests include the fundamental separation science of complex molecules, polymers and colloids, colloid chemistry and materials science and all aspects of solving large-scale chemical and physical problems with computers. His contributions to separation science include detailed theory, simulations and experimental investigations in the areas of 2D chromatography, chromatographic stationary phase calculations and mechanism, capillary electrophoresis, electrochromatography and field-flow fractionation.

He has received many awards including the Arthur Doolittle award from the American Chemical Society, the Northeastern University Distinguished Alumni Lecture award, the Douglas Leng award from The Dow Chemical Company, the Eastern Analytical Symposium Award for Outstanding Achievements in Separation Science, the L. S. Palmer award from the Minnesota Chromatography Forum and in 2015 he received the Stephen Dal Nogare award and the Uwe D. Neue award.

Determining the presence and concentration of specific molecules as indicators of health and specific diseases has revolutionized medicine. Although many definitions of the term “biomarker“ exist (1), the general idea is that some material or compound is present in a body fluid that reveals the presence of disease. Finding “smoking gun” biomarkers, those which signal an impending disease state, may be problematic in that some of these may be present at low concentrations that reside within the noise threshold of a detector. It is this theme that draws us to ask the question, “How many biomarkers may be present below the limit of detection and buried in the noise?” Some of these issues have been raised by Enke and Nagels (2) in their analysis of levels of natural substances. I will extend this discussion with recent work from my laboratory and my many collaborators.

Although this is a simple question, chromatography has a well-known problem: even with long columns and slow velocity, the component saturation is so high in a body fluid that even with high resolution mass spectrometry, large amplitude signals swamp out neighboring low-level signals causing loss of potential biomarker detection. How bad is the loss? This will be shown by generating chromatograms with statistical distributions of peak heights and retention times.

One potential aid to this is the use of two-dimensional liquid chromatography to reduce the saturation of components coming into the detector. In so many different ways, slowing down the chromatography allows one to get more effective information per unit time. In this presentation, which relies heavily on modeling, the pathways to component density reduction is explored and practical estimates reveal the difficulty of finding low-level biomarkers.